A mixture of sphingolipids, cholesterol, and free fatty acids forms the intercellular membrane
bilayers of the stratum corneum which are presumed to regulate epidermal barrier function.
Prior studies have shown that both cholesterol and fatty acid synthesis are rapidly regulated
by epidermal barrier requirements. In contrast, the importance of sphingolipids in barrier
function has not been directly demonstrated. Here, we have assessed both sphingolipid
synthesis by [3H] H2O incorporation and serine palmitoyl transferase (SPT) activity in …